da1469x: Allow DMA reads from QSPI
da1469x: Allow DMA reads from QSPI

Function da1469x_dma_write_peripheral() sets up source register to be
used by DMA transfer (Memory->Peripheral) and starts DMA.

If source address is located in QSPI flash it can still be used if
address is not from cached region 0x1600000-0x18000000.

This updates source address to be from uncached region if QSPI cached
area was used.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core